A rapid, severe, potentially life-threatening systemic hypersensitivity reaction that can affect multiple body systems.
Anaphylaxis can cause sudden difficulty breathing, swelling of the throat or tongue, wheezing, low blood pressure, dizziness, vomiting, hives, or other symptoms. It can develop within minutes of exposure to a trigger such as a food, medication, insect venom, or other substance.
Anaphylaxis requires immediate medical treatment. Epinephrine (adrenaline) is the first-line treatment, and emergency medical care is needed even if symptoms begin to improve.
QUICK FACT
Anaphylaxis does not always involve skin symptoms such as hives or a rash. A severe reaction can occur without obvious skin changes.
COMMONLY CONFUSED WITH
- Allergy: a broader term for an immune reaction to a normally harmless substance; anaphylaxis is a severe systemic allergic or hypersensitivity reaction.
- Anaphylactic shock: severe anaphylaxis accompanied by circulatory failure and dangerously low blood pressure.
SEE ALSO